LED显示屏光学性能的精确测定方法

LED显示屏作为多媒体设施的显示终端,对其光学性能的检测和评价十分重要。亮度是评价显示屏光学性能的核心量值,本文从LED显示屏的光学特性和测量要求出发,分析了影响LED显示屏亮度测量精度的主要因素,并围绕这些关键因素,介绍了常用亮度测量设备的原理及其优缺点。同时本文还介绍了具有高精度的集成化LED显示屏测量方法及系统,希望能对相关技术人员有所帮助。     

高精度光度仪器不准确度的确定

本文介绍了一种高精度光度仪器不准确度的分析和确定方法.对于作者所研制的宽波段光度仪器,在紫外-可见-近红外区确定了优于±5×10~(-4)的测量不准确度.     

基于红宝石探头的荧光光纤温度传感器的研究

基于荧光强度的温度测量原理,设计了一种利用荧光波分和时分多路传输技术,通过检测红宝石晶体的荧光强度实现温度测量系统。通过对探头的合理设计减少了激励光的泄漏,提高了系统的信噪比和灵敏度,电子信号处理采用2个绿色LED和1个红色LED驱动电路将荧光信号和参考信号分离,提高了系统的稳定性。实验表明,该系统可实现温度的高精度测量,测量温度范围300~430 K,分辨率为±0.5℃,探头误差为±3 K,信噪比为35 dB。     

非金属材料用静电测量仪的开发

文中主要介绍一种非金属材料用静电测量仪,它可以自动测量被测物体与检测仪探头的距离,并自动修正距离与电压的关系。高阻抗输入和电子开关的设计使该仪器可以保持稳定的读数,获得高精度的测量数据。     

可控温大功率LED光强空间分布测试系统的设计

发光二极管(LED)的光强空间分布特性决定了它能否满足特定场合的应用。大功率LED由于发热量大,其绝对光强空间分布(LISD)的测试也必须在特定热沉温度下进行才能得到准确可靠的结果。设计了一个可对大功率LED进行热沉温度控制且快速实现LISD自动测试的系统。该自动测试系统基于LEDGON-100测角光度计及其高精度的二维旋转台,配合测试适配器、温度控制器、光度探头、Keithley 2400源表和测试软件组成。测试软件基于Delphi程序语言开发。在控温条件下,该LISD自动测试系统稳定可靠,测试时间大大缩短,测试结果实时直观。利用该自动测试系统对具有朗伯型和蝙蝠翼型两大LISD类型的LED进行测试,获得它们的二维LISD和三维LISD。实验结果表明:随着热沉温度的增加,光强绝对值下降,而相对LISD却不变。     

灯具分布光度计现状分析

灯具分布光度计是一种大型的精密光学测试设备,是灯具分布光度测量中必备的重要设备,目前有旋转反光镜式分布光度计、运动反光镜式分布光度计和旋转灯具式分布光度计等几种结构形式,随着LED等新光源和新兴照明技术的发展,对灯具分布光度测量提出了新的挑战.本文从分布光度测量要求出发,分析了现有几种分布光度计在结构上的差异及在LED道路灯具的分布光度测量应用中存在的问题.最后,本文为分布光度计的选型提供了合理化建议及参考.     

LED器件热阻测试仪的研制

本文介绍了LED热阻测试仪的工作原理、实现方法、技术指标以及使用效果.主要研究测试系统中的程控时序控制和多路数据采集、高精度器件壳温测量与控制等技术,设计开发了LED热阻测试仪和配套恒温夹具.LED热阻测试仪的研制解决了国内LED生产和使用中迫切需要解决的热阻测试问题.对于提高我国功率LED产品的可靠性,填补国内LED热阻测试的空白,具有重要意义.     

高精度立靶测试系统角度测量电路的设计

介绍了一种新型高精度立靶密集度测试系统中角度测量电路的设计方法,该角度测量电路主要由高精度角度传感器、51单片机、多位LED显示部分构成.可用于完成线阵CCD相机仰角的实时测量和显示,并可和上位机进行多路串口通信,同时还可方便地对多台线阵CCD相机仰角进行监控.     

航空发动机用高温光纤传感探头研制技术

介绍了一种实用化的航空发动机用高温光纤传感探头研制技术。从理论上对光纤传感探头的结构进行了分析，并结合实际经验，成功地研制出航空发动机用光纤传感探头。该探头实现了在航空发动机内部高温、高灰尘环境中长时间稳定工作，在航空发动机上实现了整级叶片振幅及平衡位置变化等振动参数的在线实时测量。     

高精度重力测量技术进展

介绍了几种高精度重力测量元件，分析了现有的重力测量技术，并对其研究现状做出了评述，对重力场模型做了概括性的综述，最后展望了高精度重力测量技术的发展前景，对我国高精度重力测量技术发展提出了几点建议。     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.